The Internet Protocol Multimedia Subsystem (“IMS”) is an architectural framework for delivering Internet Protocol (“IP”) multimedia to mobile users, such as users of smart phones or tablet computers. An IMS core network (“IMS core”) permits wireless and wireline devices to access multimedia, messaging, and voice applications and services. IMS standards and specifications have been promulgated by the 3rd Generation Partnership Project (“3GPP”™). To allow the IMS core to be integrated with Internet resources, the 3GPP specifications use Internet Engineering Task Force protocols within the IMS core, such as Session Initiation Protocol (“SIP”) and Diameter. SIP is a signaling protocol used for creating, modifying and terminating two-party or multiparty sessions consisting of one or several media streams. A mobile device registers its IP address with a SIP registrar server within an IMS core by generating and sending a SIP request message. Once registered, a mobile device may subsequently establish multimedia sessions via the IMS core.
An IMS client (or IMS stack) software component on a mobile device allows one or more applications on the mobile device to register for various application services that are available on the IMS network, such as Voice over LTE (VoLTE), Rich Communication Services (RCS), Short Message Service over Internet Protocol (SMS over IP), and Presence. If the registration is successful, the mobile device application may then take advantage of the functionality offered by the application service to which it is registered. If the registration is unsuccessful, however, then the application will be unable to take advantage of the offered functionality.
In mobile telecommunications networks, such as IMS networks, operators use call detail records (CDRs) to identify and troubleshoot various problems in the network. For example, a CDR often provides valuable information that operators use to determine a root cause of one or more dropped calls, such as the particular base station that is associated with one or more mobile devices participating in a dropped call. In a typical IMS network, CDRs are generated by a telephony application server (TAS) that is located within the IMS network and logs the identity of the base station associated with the mobile device in a CDR. Thereafter, if the mobile device places or receives a call that is subsequently dropped, a network operator may check the CDR to learn the identity of the associated base station for troubleshooting purposes. If, however, the mobile device moves from the initial base station to a new base station—a process known as “handover”—then the IMS network traditionally has no knowledge of the move. As a result, the TAS is unable to update an associated CDR to accurately reflect the base station to which the mobile device is connected. Unfortunately, this lack of visibility within the IMS network poses a significant disadvantage from a network troubleshooting perspective. In particular, because CDRs are not updated after handover occurs, a network operator has no way of knowing which cellular cite a mobile device was connected to if a call is dropped after a handover occurs. In these instances, a faulty or otherwise suboptimal base station may go undetected and remain in service for an extended period of time, resulting in poor network performance, increased customer frustration, and increased difficulty and expense in troubleshooting problems in the telecommunications network. These and other problems exist with prior art systems.